Bitcoin

Bitcoin is a decentralized peer-to-peer electronic cash system that enables direct online payments between parties without financial institutions, using a distributed network to timestamp transactions into a chain and solve the double-spending problem. It was introduced in the October 2008 whitepaper "Bitcoin: A Peer-to-Peer Electronic Cash System" by the pseudonymous Satoshi Nakamoto, with the network launching on January 3, 2009, through the mining of the genesis block. BTC serves as the digital currency unit for value transfers on the network, which operates with no central authority as transactions and issuance are managed collectively by participants.

• Martti MalmiEarly developer
  • https://bitcoin.org/en/about-us
  • https://mmalmi.github.io/satoshi/

Bitcoin (BTC) has a maximum supply of 21 million coins hardcoded into the protocol, with new BTC issued solely through mining rewards that halve approximately every 210,000 blocks (roughly four years). The emission schedule began at 50 BTC per block in 2009 and has undergone multiple halvings, reaching 3.125 BTC per block following the 2024 halving, eventually transitioning to a fee-only model with no further issuance once the cap is reached. There are no allocations to teams, treasuries, investors, or other categories, as all supply enters circulation via decentralized mining; no official burns, locks, or vesting schedules apply. BTC serves as a medium of exchange and store of value, with transaction fees providing the long-term incentive for network security once issuance ends.

1. Oct 31, 2008
   Bitcoin Whitepaper Published
   Satoshi Nakamoto released the paper 'Bitcoin: A Peer-to-Peer Electronic Cash System' outlining a decentralized digital currency.
2. Jan 3, 2009
   Genesis Block Mined
   The first block of the Bitcoin blockchain was mined, launching the network with an embedded message referencing the 2008 financial crisis.
3. Jan 12, 2009
   First Bitcoin Transaction
   Satoshi Nakamoto sent 10 BTC to Hal Finney, demonstrating the first peer-to-peer transfer on the live network.
4. May 22, 2010
   First Commercial Bitcoin Transaction
   Programmer Laszlo Hanyecz paid 10,000 BTC for two pizzas, marking the first known real-world purchase using Bitcoin.
5. Nov 28, 2012
   First Bitcoin Halving
   The block reward was reduced from 50 to 25 BTC, cutting the rate of new supply issuance in half per protocol rules.
6. Feb 2014
   Mt. Gox Exchange Collapse
   Major exchange Mt. Gox filed for bankruptcy after losing hundreds of thousands of BTC in a security breach.
7. Jul 9, 2016
   Second Bitcoin Halving
   The block reward halved from 25 to 12.5 BTC, further reducing new Bitcoin issuance as scheduled.
8. Dec 2017
   Bitcoin Reaches All-Time High
   Bitcoin price peaked near $19,000 amid widespread retail adoption and ICO-related market activity.
9. May 11, 2020
   Third Bitcoin Halving
   The block reward was reduced from 12.5 to 6.25 BTC, continuing the programmed supply schedule.
10. Jan 2024
    U.S. Bitcoin Spot ETFs Approved
    U.S. regulators approved spot Bitcoin exchange-traded funds, enabling institutional investment vehicles tracking BTC price.
11. Apr 20, 2024
    Fourth Bitcoin Halving
    The block reward halved from 6.25 to 3.125 BTC, further decreasing the rate of new Bitcoin creation.

• officialWebsite
• officialBitcoin Core
• githubGitHub
• docsDeveloper Docs
• otherWhitepaper

Bitcoin has been linked to illicit use, including as the primary currency on the Silk Road darknet marketplace from 2011 to 2013, prompting U.S. Department of Justice civil forfeiture actions that seized over $1 billion in associated Bitcoin. Multiple studies, including a United Nations University analysis of 2020–2021 data, document the proof-of-work network's substantial energy consumption (173.42 TWh annually, ranking equivalent to 27th globally) and carbon emissions (over 85 Mt CO2), largely from fossil fuel sources. The 2015–2017 block size debate produced a contentious governance dispute that resulted in a hard fork creating Bitcoin Cash. Historical exchange incidents such as the 2014 Mt. Gox collapse involved significant Bitcoin losses for users.